Tower excavator



May 2, 1933. w. LEHMAN TOWER EXGAVATOR Filed Jan. 9, 1931 3 Sheets-Sheet A TTORNEYS.

May 2, 1933.

w. LE HMAN TOWER EXCAVAT OR Filed Jan. 9, 1931 3 Shets-Sheet 2 I N VEN TOR.

A TTORNEYS.

May 2, 1933. I I w. LEHMAN 1,906,760

' TOWER EXCAVATOR Filed Jan. 9, 1951 3 Sheets-Sheet 5 ATTOI/QNEYS.

Patented May 2, 1933" i WERNER IVJEHMANV, OF SOUTH COMPANY, OF SOUTH"MILWAUKE E, WISCONSIN, A CORPORATION OF DELAWARE,

rowan ExcavAroR Application filed January 0,1931. Serial No. 507,621.

Myinvention relates to new and'useful im-f provements' 1n tower excavators.

' The conventionaltower excavator is ;well

known in the excavating art, being extensively used on such projects as the levee workv along the Mississippi River. It consists in a tall tower, of very openlattice-work, known as the headtower, and afshorter'tower, called the tail tower. The former contalns themachinery for actuating, the various ropesv hereinafter described.

The head tower machinery includes three winches, forthe actuation of the three ropes required. One of these ropes, known as the track cable, is anchored to the tail tower, and serves to support a travelling carriage, from which a drag bucket is suspended. The second rope, called the-drag rope, is directly connected to the bucket, and serves to;

pull the bucket towards the head tower. The third rope, known as the back-haul rope, passes from the head tower to a sheave on the tail tower, and thence back to the car riage, its functionbeing to drag the carriage, and therefore the bucket, awayfrom the head tower.

The bucket is' raised out of, or lowered into, the work, by hauling on, or slackening, the track cable. Digging is effected by hauls ing the drag rope. Dumping is effected by slackening the drag rope, andfat the same time raising the track cable. Retracting for a new cut is effected'by pulling the back haul rope.

The foregoing is conventional, and is well known. I p

But this construction has certain disadvantages which I have overcome; notably that the conventional lattice-work head tower straddles a very. large base; so that its very great over-all dimensions, as erected,fprevent shipment in any other form than asa. great multiplicity of parts, which of necessity must remain unassembled until actually taken into the field to the place where the excavator is to be used? For this'latticework construction, I have substituted a structural mast that can. be shipped in two halves, each completely assembled, so as to require in the field nothing more than -IHI'8.&llgncertain ment and bolting together, these operations bGIIIg PQITOIITEd before erection, while the mast isstill lyinghorizontal.

There still remain, however, the disadvantages'that the erection, and also the dismantling for removal, of 'such a mast re quired the use of a gin"pole,which,having nofunction to perform-in the finished structure as erected for use,rwould be laid aside and very frequently overlooked when: the entire structure moved further along the levee. My invention contemplates the use of the-gin pole as a strut to the mast; thereby not only saving expense, but also'making that the ginopole'shall not be lost, as the'excavator I Accordingly,

the principal objects of my invention are: a I I MILWAUKEE, wrsconsm, AssIeNoR T0 BUCYRUSJEBIE proceeds along the work.

To provide a relatively! simple mast for i the head tower of a. tower excavator-system,

in place of the wide-open andcomplicated emplified in the accompanying drawings, which are hereinafter.particularly described and explained. v

Throughout the description of my inventionythe same reference number is applied to the same member or to similar members 7 On reference to the drawings,- it will be seen that: M a

Figure 1 is aside elevation, showing the essential parts of the conventional tower e'X- cavator, as described above.

Figure '2 is a side elevation, showing my head tower mast, in process of erection. Figure 3 isa side elevation, showing my the mast to an racing the mast head tower mast, erected and ready for service.

In Figures 2 and 3, I have, for the sake of clearness, omitted various details of construction not essential to my invention.

On reference to Figure 1, it will be seen that the conventional tower excavator has a head tower 10, and a tail tower 11, each being usually on creeping traction, and each being provided with machinery (not shown) for propelling itself.

Besides the machinery for propelling itself, the head tower 10 supports upon its base 12 a relatively widely straddling structural tower 13. The machinery upon the base 12 includes three drums (not shown) for actuating various ropes now to be described.

Rope 14 is the track cable, and runs from one of the said drums over a sheave 15 on the tower-13, and thence to an anchorage 15a at the top of the tail tower. From another of the drums the drag rope 16 runs over a sheave 17 situated at about mid-height on the tower 13, and thence to the bucket 18. From the third drum the back-haul rope 19 runs to a second sheave 20 at the top of the tower 13 thence around a sheave 21 at the top of the tail tower, and thence to an anchorage on the carriage 22.

The carriage 22 is adapted to run on the track cable 14, its position thereon being determined by the actuation of the drag rope 16 and the back-haul rope 19.

It will be readily seen from Figure 1 that the superstructure 13 of the conventional head tower far exceeds, in each of its dimensions, the usual railroad clearance; so that of necessity it must be shipped knocked down. In fact, ateach removal from one station to another station remote therefrom, it must be dismantled and shipped in parts, to be rebuilt at the new station. Furthermore, the conventional head towers require considerable auxiliary mechanism, such as very powerful cranes, for erecting them or taking them down for removal; whereas. with my invention, only relatively few and simple auxiliary appliances are necessary for these purposes.

Referring now to Figure 3, in which my head tower is shown in working assembly, it will be seen that there is a base 23, which is mounted on creeping traction, conventionally shown at 241. This base support-s machinery (not shown). which actuates the traction and other mechanisms.

Pivotally supported at 25, is a mast 26, of structural material. This mast has, at its head, brackets supporting two sheaves, 27 and 28. At the rear of the mast, and ap-. proximately midway of its height, a sheave 29 is supported on brackets. At the front of the mast, and in position approximately as shown, the mast carries a'pair of plates, of

which only the one, 30, on the near side of the mast, is shown, the other being similarly placed on the far side. These plates have a series of aligned holes. Upon the front of the mast is a slidable carriage 31, which is provided with holes for the insertion of pins therethrough and also through any desired hole of plate 30 and its symmetrical compan ion plate, whereby the carriage 31 may be positioned in any desired one of a number of positions. Carriage 31 carries bearings for a sheave 32.

A short distance above the carriage 31, the mast is provided with a pilot-house, 33, in which the operator is stationed, and which is provided with the various controls required.

At the back of the mast, and symmetrically placed at each side thereof, are carried two brackets;.the near one being shown at 3 1, and each being provided with a flange 35.

The mast is rearwardly supported by a pair of widely straddling back-legs, symmetrical with respect to the central, vertical, fore-andaft plane of the head tower, the near one of the back legs being shown at 36. These two back-legs are usually cross braced together, so that they may be raised and positioned as a single unit. Thus they together virtual- 1y form an A-frame or strut. In raising the mast, they serve as a gin-pole. Thus they may be regarded as a combined gin-pole and strut, or as a gin-pole-strut. The lower ends of the gin-pole strut 36 are pivoted on the base at 37, and its upper ends (or head) are forked at 38, for the reception, between the forks, of the flange 35. Atthe center 63 of each leg of the gin-pole-strut is pivoted an auxiliary strut, the near one being shown at 39. each auxiliary strut having its lower end pivoted at the side of the base 23, opposite the foot of the mast, as at 1O.

Guyropes are anchored at each side of the mast head, the near set being shown at 41, their upper anchorages being at 42, and their lower anchorages 43 being adjacent the near rear corner of the base.

From a drum 14 on the base 23, the back haul rope 15 goes to sheave 27, and thence tothe tail tower, its further course being as hercinbefore described in connection with Figure 1.

From drum 16 on base 23, the track cable 17 runs to sheave 28, and thence to an anchorage on the tail tower, as hereinbefore described.

From drum 18, the drag rope 49 goes to sheave 32, and thence to the bucket, as hereinbefore described.

From afourth drum (not shown, being hidden by drum 48 in Figure 3) on base 23, a rope 50 runs over sheave 29, thence around sheaves 51 and 52, to an anchorage at the pivot of sheave 51. Sheave 51 is fixed to the mast proper, and sheave 52 is fixed to the carriage 31; so that hauling in or paying out carriage 31.

The method of raising my head tower mast will be understood by the following description, having reference to Figure 2.

The cross section ofthe mast being relatively small, it will be possible to ship. on flat cars even the tallest mast in no more than two sections. Each section can therefore be' completely assembled before ship.

1g. I p The sections are unloadedupon the ground,

moved into alignment, and then bolted to gether. The floor of'the pilot house, and all ladders and platforms are thenattached to the mast before raising, in order to make all partsv accessible during erection. Certain of the sheaves, frames, andbearings may be left to be attached afterlhoisting. o

The assembledmast 26 is supported on the ground byany convenient means, such, for example, as is shown withrespect to one end, by the ties 53. v 4

The base, 23, is then brought up to-the mast, intoposition to allow insertion of the pivot pin at25, thereby coupling the mast to the base at the pivot upon which it is to stand when erected. I v I I o I The two back legs,/36, are then-laid on the base, 23, with their feet in position to be readily pivoted at 40. The two back legs are then -joined by the cross braces (not shown). or other elementsthat unite them into a'com-v bined gin-pole and strut. The bridle 57 and sheave 58 are then attached at the peak, and the gin-pole-strutis pivotally pinned at 40. At the same time the mast 26 is fitted with bridles 59 and 60, respectivelyxpivoted t0 the bracket 34 and to one of the. anchorages 42, for the purpose of carrying she-aves 61 and 62 respectively, which are to be used in the erecting. i. v I, The A-frame is temporarily guyedback by two ropes (not shown), one to each side, such guy ropes being supplied with releasable tensioning tackle, and being properly secured to rigidly anchored deadmen. These guys are for the purpose of preventing any sidewise motion of the gin-pole-strut during erection. I A rope isthen run in any convenient manner as, for instance, the ,rope' 62a,.shown in Figure 2, over sheaves 58, 62, 61, and attached.

to. one of the drums as at 44. .Whendrum 44 winds up this rope the gin-'pol frstrut 36'will be raised against the weight of themast 26.

As initially the mast 26 and the gin-polestrut 36 are both horizontal and therefore virtually in toggle, it is frequently necessar to initiate the upward movement-of the peak 34 ofthe gin-pole-strut, by jackingior' otherwise. I \Vhen thegin-pole-strut is thus raised to the positionshown in Figure 2, the two struts 39 are then footed into position being Winding pinned from-its footings at in the auxiliary. struts into position, the gin po lestrut, as temporarily supported by its uyropeam x used- 1 I Temporary side stays 64 are-then'fastened to the brackets 34 at the head of the, gin-polestrut, their lower endsv being anchored rat the anchorages 43.

Temporary side guys are attached to the top of the mast, then other ends being at tached to deadmen, properly anchored to the ground, These are for the purposeof sustaining the mast duringerection, andjpreventing the partially erected m'as.tfrom swinging about to the side. For thispurposefzit is convenient-to supply four uy ropes each-running at an, angle'of about-forty five degrees from the direction of the mast. Thus, if the mast head lies to the north, the four guy ropes should run approximately, to the four direction :1 northeast, southeast, north:

west, and southwest All guy ropesused on the job are provided with releasable tension ing tackle; Such guy ropes are shown 1111-.

anchored) at 54 and 55, and. tensioning tackle is indicated at 56, r As the gin-pole-strut 3.6 and. auxiliary struts 39 now-form a complete and rigid A frame, standing in the position shown in Figure. 2, themas't. may now be erected. by up the r0pe62a on (11111114 11. Dur-v ing this process the guy ropes described in the preceding watched, and are: kept properl 'tensioned, the. forwardly extending ropes eing-payed out and the rearwardly extending ropes be ing takenxin. I

The mast is thus hoisted a position very I the base 23, and all I nearly perpendicular to guy ropes are tightened. The hoisting rope is; then removed. A rope is then fastened to the top ofthe A-frame, and isroved throughzthe sheave .62 at. the top of the mast, and attached to one of thedrums or several reaches of rope 62a maybeusedfor this purpose. The temporany side stays- 64are removed. The auxiliary struts 39 are detached from the gin-pole-strut and from its footing, at 37, and'aretempm rarily laid aside. The gin-pole-strut isun 40. The rope mentioned above then raises the. gin-pole-strut out of its footings at 40, and it is drawn back to the rearof the machine, lowered into place,

and pinned at 37. The back guys attached to the top of thegin-pole-strut are then. re-

leased, allowing the gin-.pole-strut to slant forward to a position such that a slight releasing of the ropes that guy the mast. for w-alrdly willallow' the flanges 35 to slipinto thebifurcated head 318v of the gin-pole strut,

paragraph I are carefully the hoisting bridles having been just previously removed. This connection is then securely bolted.

The struts 39 are now footed at 40 and pinned at 63 to the gin-pole-strut.

Guy ropes ll are then attached as shown in Figure 3. Y

The removing of all temporary cables, bridles, and guy ropes, the reeving of all permanent ropes, and the completion of all unfinished parts, such as the operators booth 33, or the addition of any bearings and sheaves, will now put the mast in condition for use.

It will obviously not be necessary to describe the process of lowering the mast for shipment to a distant station, since it consists merely in an obvious reversal of the fore-. going processes.

Having now described and illustrated one form of my invention, I wish it to be understood that my invention is not to be limited to the specific form or arrangement of parts hereinbefore described, except in so far as such limitations are specified in the appended claims.

What is claimed is 1. In a head tower for a tower-excavator system, the combination of: a base frame; a mast, having its foot pivoted on the frame; a drag-cable sheave, adjustable throughout a range of positions on the mast; a combined gin-pole and strut, pivotable at its one end on the frame, and at its other end on the mast; a second pivot for the gin-pole-strut on the frame near the pivot for the foot of the mast; three winches, respectively serving the track cable, the back haul cable and the drag cable, certain of these winches being adaptable to hoist-the mast and the gin-pole-strut; and blocks and tackles for such hoisting.

2. Ina head tower for a tower-excavator system, the combination of: a base frame; a mast, having its foot pivoted on the frame; a combined gin-pole and strut, pivotable at its one end on the frame, and at its other end on the mast; a second pivot for the gin-polestrut on the frame near the pivot for the foot of the mast; three winches, respectively serving the track cable, the back haul cable and the drag, certain of these winches being adaptable to hoist the mast and the gin-polestrut; and blocks and tackles for such hoisting.

3. In a head tower for a tower-excavator system, the combination of: a base frame; a mast, having its foot pivoted on the frame; a combined gin-pole and strut, pivotable at its one end on the frame, and at its other end on the mast; a second pivot for the gin-polestrut on the frame near the pivot for the foot of the mast; three winches, respectively serving the track cable, the back haul cable and the drag cable, certain of these winches being adaptable to hoist the mast and the gin-polestrut; and blocks and tackles for such hoisting, part of the block and tackle for hoisting the mast being supported by the gin-polestrut.

4. In a head tower for a tower-excavator system, the combination of: a base frame; a mast, having its foot pivoted on the frame; a combined gin-pole and strut, pivotable at its one end on the frame, and at its other end on the mast; a second pivot for the ginpole-strut on the frame near the pivot for the foot of the mast; means for raising the gin-pole-strut, with its foot stepped by the foot of. the mast; said means, cooperating with the gin-pole-strut thus raised, for raising the mast.

5. In a head tower for a tower-excavator system, the combination of: a base frame; a mast, having its foot pivoted on the frame; a combined gin-pole and strut, pivotable at its one end on the frame, and at its other end on the mast; a second pivot for the gin-polestrut on the frame, near the pivot for the foot of the mast; block-and-tackle means for raising the gin-pole-strut, with its foot stepped by the foot of the mast; said blockand-tackle means cooperating with the gin pole-strut thus raised, for raising the mast.

6. The method of raising and supporting the mast of the head tower of a tower excavator system, which head tower includes a base frame, a mast, and a combined gin-pole and strut member, this method consisting in: first stepping the mast on the base frame of the head tower; then stepping the combined gin-pole and strut member on the base frame near the foot of the mast; then affixing a block and tackle joining the heads of both mast and gin-pole-strut; then utilizing this block and tackle to raise successively the gin-pole-strut and the mast; then restepping the gin-pole-strut at a point on the base frame remote from the foot of the mast; and then securing the top end of the gin-pole-strut to the mast.

7 In a head tower for a tower-excavator system, the combination of: a base frame; a mast, having its foot pivoted on the frame; a drage-cable sheave, adjustable throughout a range of positions on the mast; a combined gin-pole and strut, pivotable at its one end on the frame, and at its other end on the mast; three winches, respectively serving the track cable, the back haul cable and the drag cable, certain of these winches being adaptable to hoist the mast and the gin-pole-strut; and blocks and tackles for such hoisting.

8. In a head tower for a tower-excavator system, the combination of: a base frame; a mast, having its foot pivoted on the frame; a combined gin-pole and strut, pivotable at its one end on the frame, and at its other end on the mast; three winches, respectively serving the track cable, the back haul cable and the drag cable, certain of these winches being adaptable to hoist the mast and the gin-polestrut; and blocks and tackles ing. 7

9. In a head tower for a tower-excavator system, the combination of: a base'frame; a.

mast, having its foot pivoted on the frame; a combined gin-pole and strut, pivotable at its one end on the frame, and at its other end on the mast; three winches, respectively serving the track cable, the back haul cable and the drag cable, certainiof these winches being adaptable to hoist the mast and the gin-polestrut; and blocks and tackles for such hoisting, part of the block and tackle for hoisting the mast being supported by the gin-polestrut.

10. In a head tower for a tower-excax atoi' system, the combination of: a base frame; a mast, having its foot pivoted on the frame; a combined gin-pole and strut, pivotable at its one end on the frame, and at its other end on the mast; means for raising the gin-polestrut; said means cooperating with the ginpole-strut thus raised, for raising the mast.

11. In a head tower for a tower-excavator system, the combination of: a base frame, a

mast, having its foot pivoted on the frame; a combined gin-pole and strut, pivotable at its one end on the frame, and at its other end on the mast; block and tackle means for raising the gin-pole-strut; said block and tackle means cooperatingwith the gin-pole-strut thus raised, for raising the mast.

12. The method of raising andsupporting the mast of the head'tower of a tower excavator system, which head tower includes a base frame, a mast, and a combinedrgin-pole and strut member, this first stepping the mast on the base frame of the head tower; then stepping the combined gin-pole and strut member on the base frame; then aflixing a block and tacklejoining the heads of both mast and gin-pole-strut; then utilizing this blockand tackle to raise successively thegin-pole-strut and the mast; and

then securing the head of the gin-pole-strutto the mast. a

In testimony whereof I aflix m si ature.

v WERNER Ll H AN.

for such hoistmethod consisting in: 

